As the technology improves day by day, the semiconductor optoelectronic device makes large contribution in data transmission and in energy conversion. Take the systematic application as an example, the semiconductor optoelectronic device can be applied to the optical-fiber communication, the optics storage, and the military affairs. Classified by the way of conversion of the energy, the semiconductor optoelectronic device can be separated into three types: converting the electrical power into the light emission, such as the light-emitting diode and the laser diode; converting the light signal into the electrical power, such as the light detector; converting the light radiation energy into the electrical power, such as the solar cell.
For the semiconductor optoelectronic devices, the growth substrate plays a very important role. The essential semiconductor epitaxial structures which are used to form the semiconductor optoelectronic device are formed on the growth substrate. Therefore, how to choose a suitable growth substrate often becomes an important issue which could determine the quality of the semiconductor optoelectronic device.
However, sometimes a substrate suitable for device growth thereon is not a suitable substrate for device operation. Take the light emitting diode device for example, in the conventional red light emitting diode device manufacturing process, in order to improve the device growth quality, the opaque GaAs substrate which has the lattice constant close to that of the semiconductor epitaxial structure is often chosen to be the growth substrate. However, for the light emitting diode device which is operated to emit light, the opaque growth substrate degrades the light emitting efficiency during operation.
In order to satisfy the different requirements for the growth substrate and the operating substrate of the semiconductor optoelectronic device, the substrate transferring technology is developed. In other words, the semiconductor epitaxial structure grows from the growth substrate first, and the semiconductor epitaxial structure is transferred to the operating substrate for device operation later. Then, cutting and separating the semiconductor epitaxial structure to form the individual semiconductor optoelectronic devices after adhering the semiconductor epitaxial structure to the operating substrate.
The conventional method of cutting the growth substrate and separating the semiconductor epitaxial structure proceeds mainly by laser cutting. However, while cutting the growth substrate and separating the semiconductor epitaxial structure by laser, the opaque side product is formed because of the chemical reaction between the laser beam and the substrate and/or between the laser beam and the semiconductor epitaxial structure. The side product causes the degradation of the illumination efficiency of the semiconductor optoelectronic devices. If we remove the side products by the etchant, the surfaces of the semiconductor epitaxial structure can be destroyed simultaneously, and the yield of the structure goes down accordingly. Presently, how to cut the substrate and separate the semiconductor epitaxial structure effectively is one of the important research directions.